Instrument that can be inserted into the human body

ABSTRACT

An endoscopic instrument includes a first instrument part adapted for introduction into a cavity of a human body and having an introduction channel therein for passage of gas therethrough, and a second instrument part having a connection channel therein adapted to be connected to the first instrument part introduction channel. The second instrument part is adapted for connection to a gas source to provide gas, at a flow rate suitable for insufflation of a human body cavity, from the gas source through the connection channel to the introduction channel for introduction into the human body. A heating device heats the gas in the introduction channel to substantially the temperature of the human body.

RELATED APPLICATIONS

[0001] This patent application is a divisional of currently pending U.S.patent application Ser. No. 08/946,799, filed Oct. 8, 1997, which is aContinuation of U.S. patent application Ser. No. 08/530,150, filed Sep.29, 1995, now abandoned.

FIELD OF THE INVENTION

[0002] The present invention relates to an instrument that can beinserted into the human body, this instrument being provided with atleast one channel for fluid and, in particular a gas, which isintroduced into the inside of the body.

BACKGROUND OF THE INVENTION

[0003] By way of illustration in laparoscopic operations, it is usuallynecessary to introduce a fluid and, in particular a gas, such as by wayof illustration CO₂ into the body cavity into which incision was made inorder that the cavity does not collapse due to the “external pressure”.

[0004] With increasing duration of the operation, the number ofincisions as well as the frequency of changing the instruments requiresnot only large amounts of insufflation gas, but also high insufflationrates. This is especially the case in HF surgery and laser treatment inwhich the gas has to remove additionally occurring smoke, etc. In thepast, flow rates of a few liters per minute used to suffice, however,for some time increasingly higher flow rates are demanded.

[0005] However, even at flow rates in the 5 to 7 l/min range, thepatient suffers hyperthermia, i.e. a local drop in temperaturedistinctly below the body temperature. If (insufflation) devices havingeven higher outputs, which in the case of the devices that are availableon the market reaches up to 15 l/min, or even insufflation deviceshaving flow-through rates up to 40 l/min are employed, as described inthe patent literature, the problem of hyperthermia is even more seriousthan with conventional devices.

[0006] Therefore, it has been suggested to provide a means of heatingthe fluid in the insufflation device. In particular, with gasinsufflation devices there is the problem of heating the gas in theinsufflation device, because the gas has little thermal capacity, itcools off again in the supply tube on the way to the patient.

[0007] Thus, whenever the gas is heated only in the insufflation device,it is necessary to heat the gas to a higher temperature than is actuallydesired in order that the gas enters the human body “just” at atemperature that corresponds to the body temperature (37° C.). However,this has the drawback that the inertia of the system due to the longtube usually required is large if deviations of the temperature from thedesired temperature, i.e. the control constant, is large and thereforethe temperature constancy is small due to normal fluctuations. The gastherefore may even be introduced at a too high temperature inside thebody.

[0008] In another attempt to solve the problem of the patient'shyperthermia, notably a device sold by Wisap, Sauerlach under the name“Flow-Therme” uses an additional heatable tube that connects the actualinsufflation device to the instrument to be inserted into the humanbody.

[0009] This solution attempt, too, does not ensure optimum temperaturecontrol, because the control constant is large due the length of thetube and the possibly strongly varying surrounding conditions along thetube. Moreover, a heatable tube is less pliant and heavier due to theintegrated heating means than a normal tube. Thus, it is not as easy tohandle as a normal tube.

SUMMARY OF THE INVENTION

[0010] The object of the present invention is to ensure in introductionof at least one fluid and, in particular at least of a gas, into thebody, excellent temperature control and, in particular, constancy oftemperature of the fluid introduced into the body and, in particular, ofthe introduced gas.

[0011] An element of the present invention is that the instrument isprovided with a heating means for the fluid. The heating means can heatthe fluid and, in particular the gas, alone or in addition to a heatingmeans in the insufflation device as well as, if need be, to a“supporting” heating means in the insufflation tube. Preferred at anyrate is if the heating means of the instrument “assumes” “control” ofthe control procedure.

[0012] Disposal of the heating device in the, or immediately before the,human body, notably in or near the instrument utilized in the humanbody, ensures that optimum temperature control with short controlconstants can occur in such a manner that the fluid, that is the rinsingfluid or preferably the gas, having excellent constancy of temperatureis introduced into the body cavity.

[0013] Another advantage of the invented instrument is that theinstrument is heated by the heating means itself as well as by theheated fluid. This prevents the instrument and, in particular, anendoscope optics disposed therein, from fogging up. It is especiallyadvantageous if the heating means surrounds that part of the instrumentthat accommodates the optical system of the system and, in particular ofan endoscope, because this ensures optimum heating not only of the fluidbut also of the “sensitive” parts of the instrument.

[0014] Furthermore, a conventional supply tube of any length, inparticular, a length that can be varied from application to applicationcan be utilized between the insufflation device and the instrument.

[0015] According to certain embodiments, the heating means can beintegrated into the instrument itself. This design has not only theadvantage that the optics located in the instrument are, if need be,heated directly along with the instrument, but also, which is notapparent at first glance, that it improves the balance of the weight ofthe instrument.

[0016] Although one usually tries to design the instruments as lightlyas possible, this principle is not adhered to with laparoscopes utilizedin conjunction with a CO₂ laser. In order to compensate for the weightof the CO₂ laser or the arm connected to this laser, the instrument hasto be designed heavier than usual. This requirement can be easily met bybuilding the heating means into the instrument.

[0017] As an alternative, the heating means can be disposed in aseparate housing which is provided with a fluid inlet and a fluid outletwhich is connected via a short piece of tube to the proximal fluid inletof the instrument itself. This design not only prevents undesirabletop-heaviness in specific applications, but also permits easy upgradingof already existing instruments in such a manner that they functionallycomply with the instrument proposed by the present invention.

[0018] The use of an electric heating coil and its special design inaccordance with certain embodiments is now described.

[0019] In the aforementioned alternative, in which the heating means isdisposed outside the body, it is preferable if the heating means isprovided in the part of the instrument which remains outside the humanbody. This permits accommodating the heating means as well as parts ofthe control unit in the thicker than usually designed proximal part ofthe instrument without impairing the functions of the instrument.

[0020] Another alternative which is suited particularly for existinginstruments is now set forth. The heating means is provided in aseparate housing which is connected in one piece to the conventionallydesigned instrument. This alternative permits upgrading existinginstruments as well.

[0021] In certain embodiments, the heating means is provided with atleast one temperature sensor whose output signal is applied to a controlmeans which controls the power delivered to the heating means, therebypermitting not only control of the heating output but also control ofthe set temperature.

[0022] In another embodiment, there are provided at least twotemperature sensors whose output signals are compared for checking thefunction of the temperature sensors, thereby permitting relativelyprecise detection of malfunctions.

[0023] It is advantageous if the temperature sensor or sensors aredisposed as close as possible to the channel through which the fluidflows. Independent of the exact design of the temperature sensors, it isadvantageous if a temperature sensor which can release a safety circuitis disposed as close as possible to the distal end of the instrument.

[0024] Many different evaluation algorithms can be used to control theinvented instrument. These strategies can be stored in a program memoryand called up upon demand. In any event, any instrument and, inparticular, a trocar as well as an as such known laparoscope forsurgical applications can be employed in conjunction with the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is made more apparent in the following byway of example without the intention of limiting the scope or spirit ofthe overall inventive idea using preferred embodiments with reference tothe drawings to which are explicitly referred for the disclosure of allinvented details not explained more closely herein.

[0026]FIG. 1 shows a lateral view of a first preferred embodiment of aninvented instrument,

[0027]FIG. 2 shows a section at I-I in FIG. 1,

[0028]FIG. 3 shows a variant of the preferred embodiment depicted inFIG. 1,

[0029]FIG. 4 shows another variant of the preferred embodiment depictedin FIG. 1, and

[0030]FIG. 5 shows a second preferred embodiment of the presentinvention.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0031]FIG. 1 shows an instrument which can be inserted inside a human(or animal) body and which, without limiting the scope and spirit of thepresent invention is an as such known trocar 1 having a distal end 1′and a proximal end 1″. The trocar has a cavity 2 extending in thelongitudinal direction. Into this cavity 2 (by way of illustration) notdepicted endoscope optics can be inserted in such a manner thatadditionally a channel (having a ring-shaped cross section) is formedfor a fluid and, in particular, a gas such as CO₂. Of course, anotherchannel separated from the other insertable instruments may be providedfor the to be introduced fluid.

[0032] For the introduction of a gas in the channel formed by insertingan instrument or an already existing channel, a connection 3 isprovided, which by way of illustration can be a conventional luer-lockconnection or a tube nozzle, which connection 3 is provided with a cock4. In the case of large flow-through rates, a connection having a largerdiameter than the one which is usually used in a trocar can also beemployed.

[0033] For heating the cold gas or the gas already preheated by aheating means in a not depicted insufflation device, which is joined viaa tube to connection 3, a heating means 5 having a connection 5′ isprovided. This heating means has at least one electric heating coil 6,which surrounds the channel through which the fluid is conducted. In theshown preferred embodiment, the heating means 5 is provided in the“thicker” part of the trocar, which remains outside the human body.

[0034] Furthermore, the heating means 5 is provided with at least onetemperature sensor 7, whose output signal is applied to a not depictedcontrol or adjustment means which controls the electric power applied tothe heating coil 6. Preferably, at least two temperature sensors areprovided whose output signals are compared for checking the function ofthe temperature sensors. The temperature sensor or sensors should bedisposed as close as possible to the channel through which the fluidflows. Thus the control constants are small even in the case of highflow rates up to 40 l/min and more as well as of greatly varying flowrates.

[0035] In the following figures, the same reference numbers stand forthe same respectively similar parts, obviating renewed introduction.

[0036]FIG. 3 shows a partial section of a top view of a modification ofthe preferred embodiment depicted in FIGS. 1 and 2. In this preferredembodiment, the heating means is accommodated in a lateral addition. Theheating coil 6 is designed cube-shaped and disposed in the channel whichjoins the connection 3 including cock 4 to the cavity 2 in theinstrument and 9 stands for a casting compound.

[0037]FIG. 4 also shows a partial section of a top view of a furthermodification of the preferred embodiment depicted in FIGS. 1 and 2. Inthis modification, the heating coil is designed as a flat, electricheated element.

[0038]FIG. 5 shows a partial section of a top view and a lateral view ofa second preferred embodiment of the present invention. In thispreferred embodiment, the heating means is not accommodated in theinstrument itself, but rather in an addition which is provided with ahousing 11 which is provided with a tube nozzle 4′ which functions as aninlet and a tube nozzle 4″ which functions as an outlet. The addition isconnected to the inlet 3 of the instrument not depicted in FIG. 5 bymeans of the tube nozzle 4″ and a short tube. Located in the housing 11is a fluid channel in which the heating coil designed as a flat elementis disposed and 5′ stands for the connection for the heating means.

[0039] In the preceding the present invention has been described using apreferred embodiment without the intention of limiting the scope andspirit of the overall invention. By way of illustration, a heating meansoperating with a heat exchanger can be employed instead of an electricheating means.

[0040] Of course, the design of the heating coils is not restricted tothe preferred embodiments described in the preceding, but rather manydifferent radiators can be employed which, by way of illustration can bedesigned as a “tubular heating element”.

[0041] The instrument which in accordance with the present invention isequipped with a heating means is also not restricted to the explicitlymentioned trocars and laparoscopes described in the preceding.

What is claimed is:
 1. An endoscopic instrument comprising: a firstinstrument part adapted for introduction into a cavity of a human bodyand having an introduction channel therein for passage of gastherethrough; a second instrument part having a connection channeltherein adapted to be connected to said first instrument partintroduction channel, said second instrument part adapted for connectionto a gas source to provide gas, at a flow rate suitable for insulationof a human body cavity, from said gas source through said connectionchannel to said introduction channel for introduction into the humanbody; and a heating device for heating the gas in said introductionchannel to substantially the temperature of the human body.
 2. Theendoscopic instrument as claimed in claim 1, wherein said heating deviceis formed integrally with said second instrument part.
 3. The endoscopicinstrument as claimed in claim 1, further comprising a housing havingsaid heating device therein, said housing having a gas inlet and a gasoutlet, said gas outlet adapted for connection to said connectionchannel.
 4. The endoscopic instrument as claimed in claim 1, whereinsaid heating device comprises an electrical heating coil.
 5. Theendoscopic instrument as claimed in claim 4, wherein said heating coilis flat.
 6. The endoscopic instrument as claimed in claim 1, whereinsaid heating device is provided in said second instrument part.
 7. Theendoscopic instrument as claimed in claim 6, further comprising ahousing connected to said endoscopic instrument and having said heatingdevice therein.
 8. The endoscopic instrument as claimed in claim 1,further comprising a temperature sensor for supplying a signalindicative of the gas temperature.
 9. The endoscopic instrument asclaimed in claim 8, wherein said temperature sensor is positionedadjacent said connection channel to provide the signal to a regulatorfor said heating device.
 10. The endoscopic instrument as claimed inclaim 8, wherein said temperature sensor is positioned adjacent thedistal end of said introduction channel to provide the signal to asafety shut-off for said heating device.
 11. The endoscopic instrumentas claimed in claim 1, further comprising two temperature sensors, eachtemperature sensor supplying a signal indicative of the gas temperature;and means for comparing the signals from the two temperature sensors toprovide a signal to a regulator for said heating device.
 12. Theendoscopic instrument as claimed in claim 1, wherein said endoscopicinstrument comprises a trocar for performing an endoscopic procedure tothe human body.
 13. The endoscopic instrument as claimed in claim 1,wherein said endoscopic instrument comprises a laparoscope forperforming an endoscopic procedure to the human body.
 14. An endoscopicinstrument comprising: a first instrument part adapted for introductioninto a cavity of a human body and having an introduction channel thereinfor passage of gas therethrough; a second instrument part comprising ahousing having a gas inlet and a gas outlet and having a connectionchannel therein between the gas inlet and the gas outlet, the gas outletadapted to be connected to said first instrument part introductionchannel, and the gas inlet adapted to be connected to a gas source toprovide gas, at a flow rate suitable for insulation of a human bodycavity, from said gas source through said connection channel to saidintroduction channel for introduction into the human body; and a heatingdevice formed integrally within the housing of said second instrumentpart, said heating device for heating the gas in said introductionchannel to substantially the temperature of the human body.
 15. Theendoscopic instrument as claimed in claim 14, wherein said heatingdevice comprises an electrical heating coil.
 16. The endoscopicinstrument as claimed in claim 15, wherein said heating coil is flat.17. The endoscopic instrument as claimed in claim 14, wherein saidheating device is provided in said second instrument part.
 18. Theendoscopic instrument as claimed in claim 17, further comprising ahousing connected to said endoscopic instrument and having said heatingdevice therein.
 19. The endoscopic instrument as claimed in claim 14,further comprising a temperature sensor for supplying a signalindicative of the gas temperature.
 20. The endoscopic instrument asclaimed in claim 19, wherein said temperature sensor is positionedadjacent said connection channel to provide the signal to a regulatorfor said heating device.
 21. The endoscopic instrument as claimed inclaim 19, wherein said temperature sensor is positioned adjacent thedistal end of said introduction channel to provide the signal to asafety shut-off for said heating device.
 22. The endoscopic instrumentas claimed in claim 14, further comprising two temperature sensors, eachtemperature sensor supplying a signal indicative of the gas temperature;and means for comparing the signals from the two temperature sensors toprovide a signal to a regulator for said heating device.
 23. Theendoscopic instrument as claimed in claim 14, wherein said endoscopicinstrument comprises a trocar for performing an endoscopic procedure tothe human body.
 24. The endoscopic instrument as claimed in claim 14,wherein said endoscopic instrument comprises a laparoscope forperforming an endoscopic procedure to the human body.